With continuous scaling down of semiconductor devices, short channel effects are becoming more significant. On solution to suppress the short channel effects is to reduce the junction depth of source/drain extension regions. To form such shallow extension regions, it is necessary to adopt low-energy ion implantation in extension implantation, followed by ultra-short annealing to activate implanted ions. This poses challenges on manufacture apparatus and manufacture processes.
On the other hand, the ion implantation may cause substrate damages. Thus, an additional annealing process is needed to remove the damages.